Camera drive



May 11, 1948. w, v, BROWN ET AL 2,441,185

CAMERA DRIVE Filed Sept. 17,,1943 2 S heets sheet 1 IN V EN TORS WILLIAM V.BROWN- ATTORNEY May 11, 1948. w. v. BROWN ET AL CAMERA DRIVE Filed Sept. 17, 1943- v 2 Sheets-Sheet 2 INVENTORS WILLIAM V.BROWN BY 8 EDWIN DREW M6 K401i ATTORNEY Patented May 11, 1948 2 UNITED. STATES PATENT OFFlCE CAMERA DRIVE William V, Brown, Flushing, and Edwin H. Drew, Amityville, N. Y., assignors to Republic AviationCorporation, a corporation of Delaware Application September 17, 1943, Serial No. 502,774

2 Claims. 1

This invention relates to cameras generally and vmore specifically to an operating mechanism or drive whereby the film advancing mechanism of the camera is periodically operated from a constantiy functioning or operating source of power to successively expose a series of individual film sections or frames, one section or frame of the film being exposed upon each operation of said film advancing mechanism. Since the instanttype of camera and associated mechanism is essentially designed and intended for use in conjunction with flight test I occasioned by the continued operation of the Dower-source after an accidental or unintentional stoppage of the film advancing mechanism of the camera, or of the passage of the film through the camera.

with the above and other objects in view, as will be apparent, the invention consists in the construction, combination and arrangement of parts, all as hereinafter more fully described, claimed and illustrated in the accompanying drawings. wherein:

Fig. 1 is a front elevation of a camera illustrating the same in conjunction with the present operating mechanism or drive Fig. 2 is a plan view thereof; v

P18. 3 is a vertical section taken along line 3-3 of Fig. 2 to illustrate the signal switch and its operation;

Fig. 4 is a vertical section taken along line 4-4 of Fig. 2 longitudinally through the shafts of the operating mechanism or drive and through the connection between them; and.

Fig. 5 illustrates diagrammatically the electri- 21a] features and wiring employed by this inven- The present camera operating mechanism or drive is primarily designed to operate the'lfcamera used in conjunction with flight test equipment of the type disclosed in the George T. Burrell application Serial No. 402,069 filed July 12, 1941, which on June 12, 1945, matured into Patent No. 2,378,182. Essentially this invention resides in 2 a the camera operating mechanism or drive whereby the film advancing mechanism of the camera is periodically and regularly operated to successively expose one frame or section of the con-- 5 tinuous film within the camera and to accomplish this without any supervision or control on the part of the pilot. Thus the operation of the device is initiated by the pilot after which its operation may be entirely ignored, the pilot being at all times informed as tothe normal operation of the drive or operating mechanism and consequently is instantly apprised of its failure to operate.

\ Reference being had more particularly to the drawings iii indicates a carrying or base plate for the camera and its operating mechanism or drive. At one end of the plate I" is mounted the camera ii of any suitable standard construction. The film advancing mechanism (not shown) of this camera ii is operated to periodically expose one section or frame of the film at regular periodic intervals. 'The camera Ii may be of any suitable construction, provided, however, that it hasa film advancing mechanism at a time.

For this purpose the camera is provided with 80 the projecting shaft i2 for the operationpf its film advancing mechanism, and for each rotation of the shaft I! one section or frame of the film is exposed. Manifestly, therefore, by regulating the speed of rotation of the shaft I 2, the

length of the intervals between the exposures of sections or frames of the film can be determined.

A reversible electric motor I! is mounted on the carrying plate It with its shaft ll longitudinally aligned or coextensive with the shaft I! of the film advancing mechanism of the camera ii. The shaft ll of this motor l3 carries a disc i5 mounted on its terminal by collar I 6 and fixed thereto by a pin i1 passing through both the collar i8 and the shaft ll. A similar disc i8.

having a collar i9, is mounted on the protruding terminal of the shaft I! of the film-advancing mechanism and is secured thereto by the pin 20 piercing the collar l9 and the protruding end ofthe shaft I2. The pin 20 is so constructed that it will be sheared off should the film advancing mechanism become inoperative or the film jam in the camera thereby disconnecting the continuously operating motor I! from the shaft I2.

This is an additional precautionary measure to ever, that it has a film advancing mechanism whic which feeds the film through the camera for the periodic exposure of one frame or section thereof protect the camera mechanism which mayor may no be employed as circumstances dictate.

The iscs II and II, which are in effect clutch plates, are of substantially the same diameter, and have their faces positioned in close proximity, if not in actual functional contact. The disc it. which isthe driven clutch plate, is provided with a concentric groove II in its inner face in which is situated a clutch bearing member 22 of any suitable material. The disc ll, carried by the motor shaft M, has an outstanding or projecting boss II and through the disc II and the boss I! are threaded a series of screws II, each screw being provided with a bearing head 24 at its inner end. A ring or annuls of friction material is interposed between the bearing member 2! of the plate is and the several bearing heads 24 of the screws 23, these said bearing heads I being seated in sockets formed for the reception thereof in the adjoining face. of the friction ring 28. Thus the heads 2 operating in sockets in the friction ring 2! not only exert an adjustable pressure on the friction ring is but hold it from any rotary or "bodily movement relative to the disc II in a plane parallel to the plate ll.

Pins 22' or other suitable fastening means on the inner surface of the bearing member fl'engage the disc l8 and prevent any displacement of the member 22 or rotary movement thereof relative to the plate It in a plane parallel to the plane of said plate.

When the screws 23 exert the required pressure upon the friction ring 25 and it in turn has operative engagement with the bearing member 22, the discs I! and II are frictionally connected for rotation in unison, so that as the shaft ll of the motor ll rotates so will rotate the shaft I! of the film advancing mechanism of the camera II. This pressure'between the plates II and I! can of course be regulated by the threaded adlustment of the screws 23. To prevent any retrograde movement of the screws or unintentional change in their adjustment a coil spring 2. surrounds the stem of each screw 23 between the outer face of the disc I! and the head of the screw, and being always compressed, exerts sunlcient pressure on the head of the screw to prevent any play between the threads of the screw and the threads of the aperture in the plate It and also tends to prevent any unintentional rotary movement by the screw.

From the foregoing it becomes manifest that the frictional engagement between the discs I! and is may 'be adjusted by the screws II to determine the point at which the load on the shaft I! will convert the contact from frictional driving I engagement into a slipping non-driving contact. Thus if the load on the shaft l2 increases beyond the adjusted limit from any reason the driving contact between the discs I! and Il becomes a slipping contact and the rotation of the shaft It will not rotate the shaft I! of the camera.

In order to provide means for informing the pilot as to the continued but periodic operation of the camera, the disc It carries a peripheral camprojection 21, which makes one complete rotation with the disc is for each rotation of the shafts II and H. A bracket 28, positioned adjacent to the discs II and I8, carries a switch 2! under the control of a projecting spring switch lever III overlying the path of movement of the cam 21 and terminating in the approximate plane of the disc It. As the disc l8 rotates under the influence of the motor II, the cam 11 will contact the spring switch lever II, once for each rotation 7 4 of the shafts II and H and th'ediscs II and II, and for each time it so contacts the switch lever 3|, the switch 2! will be closed and visible or other signal under the observation of the pilot will be operated.-

Thus the operator is at all times apprised of the operating conditions of the camera and of its driving mechanism. For instance, if the con- I nection between the plates II and II is loose, or

becomes so damaged that the rotation of the shaft ll will have no effect upon the shaft II, the

. disc II will not rotate. and consequently the signal will not be operated by the cam 21. If the film advancing mechanism of the camera becomes 15 inoperative or the film becomes jammed for any reason, a braking effect will be produced on the shaft l2 and its discs II and without the iniiuence of the motor and its shaft ll the shaft ll would cease rotating. Under these circumstances 'gthe shaft ll ceases to drive the shaft I! because of the slippage between the cooperative faces of the discs I! and II or because of the shearing of the pin whereupon the rotation of the disc II is halted. When this occurs the signal to the 5 operator under the control of the cam 21 ceases 'to operate periodically or upon each revolution of 'the disc l8. thereby informing the pilot of the failure of the apparatus. Also as the shaft l2 ceases its rotation under these conditions the camera ii and its mechanism are protected.

The embodiment of the present invention illustrated in the drawings and here described, in-

- cludes a reversible electrical motor ll. though it is to be understood that any. type of motor may be used in lieu thereof. In Figure 5 is illustrated diagrammatically the electrical, connections for the control of the motor and for the operation of the signal. In the present preferred form of the invention, the signal comprises the lamp ll 40 connected on one side to ground and on the other side to one terminal of the switch 20. The opposite terminal of the switch II is connected to the common binding post II and thence to one side of a control switch II. The opposite side of the control switch I! is connected through battery B to ground. The common binding post II is also connected to one winding ll of the reversible motor ll, while the opposed winding 84 of the motor is connected to ground thro sh' so rheostat 35. Since the motor rotates only in one direction in the functioning of the present invention, the second winding 34 thereof in circuit with the rheostat 35 is used as a brake to reduce or adjust the speed of the motor II when the occasg sion arises; thus the full power of the motor is always available through the winding II for its rotation in a clockwise direction, whereby the motor will always effectively start and operate the camera II and at the same time the secondary winding under the control of the rheostat ll acts as a brake in reducing its speed when desired. A graduated scale 31 is provided in conlunction with the knob 38 of the rheostat, so that the .R. P. M. of the motor I! can be accurately as and-quickly determined. As the rheostat II is set with respect to the scale 30, so will the revolutions permitted of the motor be determined and n the revolutions of the shaft i2 likewise be determined.

7 When the pilot desires the device to operate. 1 he merely closes the switch 32, starting the motor 1. In a flight-test recording device for making photographic records of the instruments in an aircraft comprising the combination with a camera. a film-advancing mechanism for the camera, a drive shaft for operating the filmadvancing mechanism and an electric motor for rotating the drive shaft, of a signal device for indicating the condition of operation of the flimadvancing mechanism, said signal device comprising a cam mounted on the drive shaft, a frangible connection between the drive shaft and motor, a switch interposed in the path of movement 0! said cam and movable to open and closed position by said cam, an electricaicircuit including said switch. a source of electric current and a signal lamp, and means for regulating the speed 6 of rotation of said motor and thereby determining the periodic time intervals at which said nimadvancing mechanism will operate.

2. In a fiight-test recording device as set forth in claim 1, in which the electric motor is of the reversible type.

WILLIAM V. BROWN. EDWIN H. DREW.

' REFERENCES CITED The following references are of record in the tile of this patenti UNITED STATES PATENTS Number Name Date 1,656,361 Tessier Feb. '7, 1928 1,759,630 Rinaldy May 20, 1930 1,857,204 Littlefleld May 10, 1932 1,928,434 Pomeroy et al Sept. 26, 1933 2,051,785 Foster Aug. 18, 1936 2,083,646 Fuller June 15, 1937 2,156,440 Veber May 2, 1939 2,193,515 Kessel Mar. 12, 1940 2,260,299 Cunningham et al.-- Oct. 28, 1941 2,370,966 Jochum Mar. 6, 1945 

